Earth Resources
Mineral Resources
• Building
• Metallic Minerals
Stone, Sand, Gravel,
– Non-ferrous: Copper, Zinc,
Limestone
Tin, Lead, Aluminum,
Titanium, Manganese,
• Non-metallic Minerals
Magnesium, Mercury,
Sulfur, Gypsum, Coal,
Vanadium, Molybdenum,
Barite, Salt, Clay,
Tungsten, Silver, Gold,
Feldspar, Gem Minerals,
Platinum, Rare Earths
Abrasives, Borax, Lime,
• Energy Resources
Magnesia, Potash,
Phosphates, Silica,
– Fossil Fuels: Coal, Oil,
Fluorite, Asbestos, Mica,
Natural Gas
Lithium
– Uranium
• Metallic Minerals
– Geothermal Energy
– Ferrous: Iron and Steel,
Cobalt, Nickel
Types of Ore Deposits
Magmatic
• Pt, Cr, Fe, Ni, Ti, Diamond
Pegmatite
• Li, Be, U, Rare Earths,
Feldspar, Mica, Gems
Hydrothermal
• 600 C: W, Sn
• 400 C: Au, U, Ag, Co, Mo
• 200 C: Cu, Zn, Cd, Pb
• Cool: Hg, As
Sedimentary Rocks
• Fe, Cu, U, Mn, Mg
Weathering
• Secondary Enrichment:
– Cu, Ni
• Soils
– Al, Ni
Placer
• Pt, Au, Sn, Ti, W, Th, Rare
Earths U (Fossil), Gems
Concentration Factors and Economics
• Natural Abundance
• Geologic Processes to Concentrate Element
– Most involve water
• Intrinsic Value of Material
• Cost of Extraction from Earth
– Gold versus Gravel
Prospecting and Exploration
Satellite and Aerial
Photography
Remote Sensing
Geological Mapping
Magnetic Mapping
Gravity Mapping
Radioactivity Mapping
Geochemical Sampling
Electrical Sounding
Ground-Penetrating
Radar
Seismic Methods
– Reflection - Detailed
but Expensive
– Refraction - Cheap but
Not Detailed
Core Sampling and Well
Logging
Economic Factors in Mining
•
•
•
•
•
Richness of Ore
Quantity of Ore
Cost of Initial Development
Equipment, Excavation, Purchase of Rights
Operating Costs: Wages, Taxes, Maintenance,
Utilities, Regulation
• Price of the Product
• Will Price Go up or down?
Life Cycle of a Mine
• Exploration
• Development
• Active Mining
– Excavation
– Crushing, Milling, Flotation, Chemical
Separation
– Smelting and Refining
– Disposal of Waste (Tailings)
• Shut-down
Issues in Mineral Exploitation
Who Owns (Or Should Own) Minerals?
• Landowner,
• Discoverer,
• Government
Unclaimed Areas:
• Sea Floor,
• Antarctica
Who Controls Access for Exploration?
• Remote Sensing vs Privacy
Problems of Mining
Safety
• Mine Wastes
• Pollution
• Dust
• Noise
Sulfur (H2SO4)
• Acid Rain
• Acid Runoff
• Dissolved Metals (Fe,
Cu, Zn, As...)
Environmental
Problems
• Exploration
• Construction and
Operation
Economic Impact
• "Boom and Bust"
Cycles
Geothermal Energy: A Free Lunch?
Environmental Problems
of Geothermal Energy
• It is Finite
• Heat Sources Can Be
Exhausted (Geysers,
California)
• Sulfur Emissions
• Disposal of Mineralized
Brines
Technical Problems of
Geothermal Energy
• Corrosion
• Mineral Deposition in
Pipes
• Non-Productive gases
(Carbon dioxide,
methane, etc.)
• Low Temperatures
• Low Thermodynamic
Efficiency
Thermodynamic Efficiency
• Eff. = (Ti - Tf)/Ti
• T = Degrees Kelvin = Degrees C + 273
• Ti = initial temperature
• Tf = final temperature
Thermodynamic Efficiency
Automobile Engine
• Ti = 1200 C = 1473 K
• Tf = 500 C = 773 K
• Eff = (1473 - 773)/1473 = 48%
Typical Steam Power Plant
• Ti = 700 C = 973 K
• Tf = 200 C = 473 K
• Eff = (973 - 473)/973 = 51%
Thermodynamic Efficiency
Geothermal Power Plant
• Ti = 150 C = 423 K
• Tf = 80 C = 353
• Eff = (423 - 353)/423 = 17%
Actual achieved efficiencies
• Automobile on Highway: about 5%
• Geothermal Plant: 5% or So, Sometimes
less than 1%
Where the Oil Is
The Geography of Oil
Hubbert Curves
• In 1956, Oil geologist M. King Hubbert noted that
rates of oil production follow a bell-shaped curve.
• Cumulative production follows a slanting S- curve
• Production lags discovery by about ten years.
Hubbert’s 1956 Prediction
Where We Stand Today
What if We Find More Oil?
• Even a huge
increase in total
oil has very little
effect on the
peak and
decline of
production.
• Why? We waste
most of it on
inefficient uses.
One Solution: Limit Production
Is There a Lot More Undiscovered Oil?
• 80 per cent of oil being produced today is from fields
discovered before 1973.
• In the 1990's oil discoveries averaged about seven
billion barrels of oil a year, only one third of usage.
• The discovery rate of multi-billion barrel fields has
been declining since the 1940's, that of giant (500million barrel) fields since the 1960's.
• In 1938, fields with more than 10 million barrels
made up 19% of all new discoveries, but by 1948 the
proportion had dropped to only 3%.
Oil Discovery Rates
Some Relevant Quotes
The internal-combustion engine used for
automobiles is a fragile device compared with
other prime movers -- even compared with
the internal combustion engines used for
diesel- electric locomotives that have been
known to go over a million miles without
mechanical overhauling.
Some Relevant Quotes
... the energy-system efficiency of the motor car
with petroleum motor fuel is, thus, 5 percent
... no one is proud of this accomplishment -least of all the automotive-design engineers ...
The trouble is, every time the design engineer
manages to save a few BTU it is more than
spent answering the clamor for softer tires, for
radio, for better heaters, more lights, cigarette
lighters and possibly even air conditioning.
Some Relevant Quotes
Histories written a few centuries hence may
describe the United States as a nation of such
extraordinary technologic virility that we
succeeded in finding ways of dissipating our
natural wealth far more rapidly than any other
nation. At any rate, we are having a wonderful
time doing it. From the discussions in the
earlier chapters of this book it is clear that the
problem of energy for the United States is not
one of the dim future. It is upon us now.
Some Relevant Quotes
Our imports of petroleum are small but each
year they become larger. By 1960 they are
likely to be quite substantial. By 1970 they will
almost certainly be huge -- if foreign oil is still
available then in sufficient quantity... This tiny
period of earth's life, when we are consuming
its stored riches, is nearly over ... Fortunately
for us there is still time for fundamental
research [on alternative energy sources]. But
not too much time.
Some Relevant Quotes: Source
Eugene Ayres and Charles A
Scarlott, 1952; Energy Sources -The Wealth of the World,
McGraw-Hill, 344p.
Petroleum is a Syllogism
• There is a finite amount of it in the
world
• We are using it and not replacing it
• Therefore we will eventually run
out of it
• Any of this not clear?
The End of Cheap Oil
• Known petroleum can last at least a couple of
centuries more, but…
• It only flows through the rocks so fast.
• No amount of drilling will make it flow faster,
and careless drilling can shorten the lifetime
of an oil field.
• Sometime in the 21st century, global demand
will outpace production capacity and…
• Oil will go to the highest bidder.
Some Final Thoughts
What have you personally done to deserve access to
petroleum at any price?
If you think energy is such a scam, get up off your butt
and do something about it.
• If you think there is undiscovered oil out there, study
geology and engineering and find it!
• If you think synthetic oil is the answer, major in chemistry
and make it happen.
• If you think the answer is alternative energy sources, major
in physics and engineering and develop them.
• Don’t major in Plain Vanilla Studies and then complain when
other people don’t provide you with energy for free.